IE

Question 1

“typical MOs” for IE

Answer 1

Viridans streptococci

Streptococcus gallolyticus (formerly S. bovis)

HACEK group: Haemophilus spp, Aggregatibacter (formerly Actinobacillus actinomycete comitants), Cardiobacterium hominis, Eikenella spp, and Kingella kingae

Staphylococcus aureus

Community-acquired enterococci, in the absence of a primary focus;

Single positive blood culture for Coxiella burnetii or antiphase I IgG antibody titer >1:800*

Question 2

what is the special protein that some staph aureus have that makes them particularly good at causing IE?

Answer 2

it is the fibronectin binding protein

Question 3

what is the most common cause of early prosthetic valve (<2 months) IE?

Answer 3

40% are culture neg
20% ENT source
17% coag neg staph

Question 4

what is the most common cause of prosthetic valve IE (2 - 12 months after surgery)?

Answer 4

27% are coag neg staph
13% culture neg
7% is staph aureus

Question 5

what is the most common cause of late prosthetic valve IE? (>12 months)

Answer 5

staph aureus makes up 25%
20% enterococcus
12% culture neg
9% coag neg staph

mitral is more common than aortic

Question 6

what is the greatest risk factor for IE?

Answer 6

previous IE is the strongest

relapse is when it is the same MO within 6/12

reinfection is different bug > 6/12

Question 7

what is the most common cause of pacemaker associated ie?

Answer 7

coag neg staph is 54%

staph aureus is 23%

Question 8

if you think someone has brucella infective endocarditis, and blood cultures have failed to become positive, what is the next test?

Answer 8

you can do serology

or you could do a bone marrow

Question 9

what has a worse prognosis: early or late prosthetic valve endocarditis?

Answer 9

early has a 33-100% mortality

late 25-50% mortality

Question 10

what are the risk factors for death (from IE)?

Answer 10

age
staph aureus
CVA and embolic events
heart failure
health care associated IE

Question 11

what are the recommended empiric treatment for native valve IE?

Answer 11

acute presentation:
vanc plus gent

indolent:
amoxicillin plus gent

if pen allergy - vancomycin

Question 12

what is the empiric treatment for prosthetic valve IE?

Answer 12

if early (12 months): as per native valves
-- vanc plus gent or amoxi plus gent

Question 13

which of the strep are associated with invasion and abscesses?

Answer 13

Strep Anginosus (milleri)

Question 14

which of the strep is most likely to have the immunoloigically mediated signs?

Answer 14

strep viridans (sanguis and mutans)

Question 15

which population is Group B strep IE associated with?

Answer 15

preggos
immunosuppressed
alcoholics

these ones need surgery for cure

Question 16

what are the indications for urgent surgery in IE?

what about semi-urgent?

Answer 16

if heart failure due to IE, this is URGENT, esp if cardiogenic shock or refractory pulm oedema

semi-urgent:

uncontrolled infection - particularly fungal, s. aureus and s. lugdunenensis, group B strep
prevention of embolism
early PVE > late PVE

Question 17

what is the most common site, and most common bug for IE in IVDU?

Answer 17

tricuspid and s. aureus

usually only 1 in 3 have signs though

but might be symptomatic with fever, chills and pleuritic chest pain

Question 18

what is the most common cause of culture neg endocarditis?

Answer 18

apparently it is antibiotics being given prior to BCs

Question 19

what are the recommended pre-procedure antibiotic prophylaxis for dental procedures?

what about GIT/GUT procedures?

Answer 19

for dental it is:
amoxil 2g oral 1 hour prior
if pen allergy, clinda or cephalex orally 1 hour prior

for GIT/GUT where the mucosa might be crossed for biopsies, we need to cover enterococci:
IV amoxil 2g 30 minutes prior

if pen allergy:
vanco 1g given 30 min prior
or teicoplanin just before

Question 20

which of the congenital heart defects should have prophylaxis?

1. VSD
2. MVP
3. tetralogy of Fallot
4. asd

Answer 20

it’s only cyanotic heart disease

apparently even a VSD doesn’t get prophylaxis with a dental procedure these days

however, if the tooth is infected, then they should have antibiotics for the tooth infection

Question 21

what sorts of people get antibiotic prophylaxis in Australia?

Answer 21

any one with prosthetic material

anyone with cyanotic heart disease